1. Field of the Invention
The present invention relates to an image information reading apparatus for being loaded with a cassette storing a stimulable phosphor sheet, removing the stimulable phosphor sheet from the cassette, reading radiation image information recorded on the stimulable phosphor sheet, and then returning the stimulable phosphor sheet to the cassette.
2. Description of the Related Art
There has been known a radiation image recording and reproducing system for recording radiation image information of a subject, such as a human body, using a stimulable phosphor, and either reproducing the recorded radiation image information on a photosensitive medium such as a photographic film or the like or displaying the recorded radiation image information on a cathode-ray tube or other display units.
When a radiation energy such as X-rays, xcex1-rays, xcex3-rays, electron beams, ultraviolet radiation, or the like is applied to a certain phosphor, it stores part of the applied radiation energy. When stimulating light such as visible light is subsequently applied to the phosphor, the phosphor emits light depending upon the stored radiation energy. Such a phosphor is referred to as a stimulable phosphor. A stimulable phosphor is usually used in the form of a sheet which is referred to as a stimulable phosphor sheet.
The radiation image recording and reproducing system includes an image information reading apparatus comprising a reading unit for reading image information recorded on a stimulable phosphor sheet and an erasing unit for erasing remaining image information from the stimulable phosphor sheet after the recorded image information has been read therefrom by the reading unit. The image information reading apparatus has a cassette loading section for receiving therein a cassette which stores a stimulable phosphor sheet on which radiation image information of a subject has been recorded by an external exposure unit.
After the cassette is inserted into the cassette loading section, the lid of the cassette is opened, and the stimulable phosphor sheet is removed from the cassette by a sheet feeding mechanism. The removed stimulable phosphor sheet is then delivered to the reading unit by a sheet delivering mechanism. The reading unit reads the radiation image information from the stimulable phosphor sheet by applying stimulating light to the stimulable phosphor sheet. Thereafter, the stimulable phosphor sheet is delivered to the erasing unit, which erases remaining image information from the stimulable phosphor sheet. The stimulable phosphor sheet is then delivered back and inserted into the cassette in the cassette loading section.
Some image information reading apparatuses have a cassette loading section for being loaded with a single cassette, and other image information reading apparatus have a cassette loading section for being loaded with a plurality of cassettes. In the former type of image information reading apparatus, the loaded cassette is replaced with a cassette each time the image reading and erasing process is finished on the stimulable phosphor sheet from the loaded cassette. In the latter type of image information reading apparatus, stimulable phosphor sheets are successively delivered from the corresponding cassettes to the reading unit and the erasing unit, and the processed stimulable phosphor sheets are successively returned to the respective cassettes, so that the stimulable phosphor sheets can efficiently be processed.
The operator of the latter type of image information reading apparatus manually handles a plurality of cassettes as follows: Since the operator finds it very difficult to hold all the cassettes together and then insert the cassettes, one by one, into the cassette loading section, it is customary for the operator to first place the cassettes on a table positioned alongside of the image information reading apparatus, and then to manually pick up and insert the cassettes, one by one, into the cassette loading section.
However, the above conventional cassette loading process is tedious and time-consuming. In addition, although an extra space for placing the table therein is needed near the image information reading apparatus, existing space limitations around the image information reading apparatus may sometimes prevent such an extra space from being provided. Furthermore, when the operator handles cassettes containing processed stimulable phosphor sheets, the operator must unload and place those cassettes, one by one, on another table.
The former type of image information reading apparatus, which is loaded with a single cassette at a time, also requires a table for placing thereon a plurality of cassettes containing unprocessed stimulable phosphor sheets, and also a table for placing thereon a plurality of cassettes containing processed stimulable phosphor sheets, for allowing the operator to handle cassettes efficiently.
The former type of image information reading apparatus is disclosed, for example, in Japanese Laid-Open Patent Publication No. 5-333456. As shown in FIG. 12, the reading apparatus comprises an apparatus housing 1, and a loading section 3 for loading a cassette 2 on the upper side of the apparatus housing 1. The loading section 3 has a feeder 5 disposed therein for removing a stimulable phosphor sheet 4 stored in the cassette 2. A feeding section 6 is provided near the feeder 5, and an erasing unit 7 is mounted on a vertical feed path of the feeding section 6. The lower part of the feeding section 6 is curved from a vertical direction into a horizontal direction, and a reading unit 8 is disposed at the end of the feeding section 6.
According to the former type of the conventional reading apparatus, the erasing unit 7 is aligned with the vertical part of the feeding section 6. Thus, especially, the dimension H of the apparatus housing 1 tends to be relatively large. However, it is a recent demand that various equipment is intensively placed in a limited space, so that a space for placing equipment is desired to be minimized.
It is a major object of the present invention to provide an image information reading apparatus which does not require a dedicated table for placing cassettes thereon, and which allows the operator to handle the cassettes efficiently.
It is another object of the present invention to provide an image information reading apparatus which minimizes a space for placing the entire apparatus.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.